It was meant to be a carbon-neutral adventure to fire the imaginations of 25,000 schoolchildren.

Raoul Surcouf, 40, a landscape gardener from Jersey, and Richard Spink, 32, a physiotherapist from Bristol, shunned the polluting aircraft normally used to reach Greenland's polar ice cap and set sail in Fleur, a 40ft yacht fitted with solar panels and a wind turbine. Schools were poised to follow their green expedition online; once the duo had skied across the Arctic wastes they had hoped to boast of the first carbon-neutral crossing of Greenland.

On Friday, nature, displaying a heavy irony, intervened. After a battering by hurricane force winds, the crew of the Carbon Neutral Expeditions craft had to be rescued 400 miles off Ireland.

As if their ordeal wasn't terrifying enough, their saviour seemed chosen to rub salt in their wounds: a 113,000-ton tanker, Overseas Yellowstone, carrying 680,000 barrels of crude. In a statement from the tanker, Spink said: "We experienced some of the harshest conditions known, with winds gusting hurricane force 12 ... The decision was made that the risk to our personal safety was too great to continue."

In truth, the crew could not afford to be choosy. They were in a life-threatening predicament, and heaped thanks on Captain Ferro, the tanker's skipper, and his crew for being "outstanding in the execution of the rescue". But the rather awkward twist was not lost on Spink, who ruefully noted afterwards that "the team are now safely and ironically aboard the oil tanker" as they headed to Maine, where they are due to arrive in three days.

Their ordeal began on Thursday morning. With his vessel blasted by 60-knot gusts, skipper Ben Stoddart deployed the anchor to try and slow the craft down, only for a wave to come over the stern, causing the first of three capsizes. With the navigation instruments failing and structural damage, the crew alerted Falmouth coastguard. After two further waves lashed the boat, destroying the solar panels and generator, coastguards were asked to mount a rescue.

"They are extremely relieved to just be alive," said Jess Tombs, a spokeswoman for the expedition. Were they feeling sheepish about being rescued by an oil tanker? "They were just relieved," she said. "We don't want to think about what the outcome would have been if they hadn't."